Display device, display system, and display control method

ABSTRACT

A projector includes a projecting section configured to display an image, an image interface to which an image signal corresponding to a first image is input from a personal computer, an image processing section configured to generate a second image obtained by reducing visibility of the first image based on the image signal, and a first control section configured to, when a first condition is satisfied, cause the projecting section to display the second image and, when a second condition is satisfied, cause the projecting section to display the first image.

The present application is based on, and claims priority from JPApplication Serial Number 2020-115459, filed Jul. 3, 2020, thedisclosure of which is hereby incorporated by reference herein in itsentirety.

BACKGROUND 1. Technical Field

The present disclosure relates to a display device, a display system,and a display control method.

2. Related Art

There has been known a technique for preventing a display, device from,displaying information that a user does not desire to make public (see,for example, JP-A-2011-191674 (Patent Literature 1)). In the techniquedescribed in Patent Literature 1, an imaging device including a monitoris capable of outputting an image to an external display device. Theimaging device displays the image on the monitor before outputting theimage to the display device. The user performs publication setting forthe displayed image. The imaging device stores the image, for which thepublication setting is performed, in a publication-image storing sectionand outputs the image stored in the publication-image storing section tothe display device.

The user sometimes cannot check beforehand an image to be displayed, forexample, when the display device starts to display the image. A methodof preventing display of an image not desired to be made public in sucha case has not been proposed.

SUMMARY

An aspect of the present disclosure is directed to a display deviceincluding: a display section configured to display an image; aninterface circuit to which an image signal corresponding to a firstimage is input from an image supply device; an integrated circuitconfigured to generate a second image obtained by reducing visibility ofthe first image based on the image signal; and a processor programmedto, when a first condition is satisfied, cause the display section todisplay the second image and, when a second condition is satisfied,cause the display section to display the first image.

Another aspect of the present disclosure is directed to a display systemincluding: a display device including a display section configured todisplay an image; and an image supply device configured to input animage signal corresponding to a first image to the display device. Thedisplay device includes: an integrated circuit configured to generate asecond image obtained by reducing visibility of the first image based onthe image signal; and a processor configured to, when a first conditionis satisfied, cause the display section to display the second image and,when a second condition is satisfied, cause the display section todisplay the first image.

Still another aspect of the present disclosure is directed to a displaycontrol method includes: generating a second image obtained by reducingvisibility of a first image; displaying the second image when a firstcondition is satisfied; and, displaying the first image when a secondcondition is satisfied.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing an example of the configuration of a displaysystem.

FIG. 2 is a block diagram of a projector.

FIG. 3 is a functional block diagram of a control system of theprojector.

FIG. 4 is a block diagram of a personal computer.

FIG. 5 is a diagram showing an example of a first image d splayed by theprojector.

FIG. 6 is a diagram showing an example of a second image displayed bythe projector.

FIG. 7 is a diagram showing another example of the second imagedisplayed by the projector.

FIG. 8 is a diagram showing still another example of the second imagedisplayed by the projector.

FIG. 9 is a flowchart showing the operation of the projector.

FIG. 10 is a flowchart showing the operation of a projector in a secondembodiment.

FIG. 11 is a flowchart showing the operation of a projector in a thirdembodiment.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Embodiments are explained below with reference to the drawings.

1. First Embodiment

1-1. Configuration of a Display System

FIG. 1 is a diagram showing as example of the configuration of a displaysystem 1.

The display system 1 includes a display device and a personal computer200. In a first embodiment, a projector 100 is explained as an exampleof the display device.

The projector 100 is connectable to external devices that transmit imageinformation. These devices are called image supply device. The projector100 projects image light PL onto a screen SC based on the imageinformation transmitted from the image supply device. Consequently, aprojected image P is displayed on the screen SC. The operation of theprojector 100 projecting the image light PL is referred to as display inthe following explanation.

In FIG. 1 , an example is shown in which the personal computer 200 isconnected to the projector 100 as the image supply device. The personalcomputer 200 is connected to the projector 100 by, for example, a cable10. The cable 10 is, for example, an HDMI (Hight-Definition MultimediaInterface) cable conforming to an HDMI standard. In this configuration,the personal computer 200 executes communication conforming to the HDMIstandard with the projector 100 and transmits data including imageinformation and control data to the projector 100. A configuration maybe adopted in which the projector 100 and the personal computer 200 areconnected by wireless communication and wirelessly transmit the dataincluding the image information. HDMI is a registered trademark.

In FIG. 1 , an example of floor installation for placing the projector100 on a floor in front of the screen SC is shown. However, theprojector 100 may be suspended from a ceiling and set. In thisembodiment, as an example, the projector 100 projects the image light PLonto a plane screen SC. However, a projection target is not limited tothe screen SC and may be a plane such as a wall surface of a building ormay be a curved surface or an uneven surface.

1-2. Configuration of the Projector

FIG. 2 is a diagram showing an example of the configuration of theprojector 100 according to this embodiment.

The projector 100 includes a projecting section 110 and a drivingsection 120 that drives the projecting section 110. The projectingsection 110 forms an optical image and projects the image onto thescreen SC to display the image on the screen SC.

The projecting section 110 includes a light source section 111, a lightmodulating device 112, and a projection optical system 113. The drivingsection 120 includes a light-source driving section 121 and alight-modulating-device driving section 122. The projecting section 110corresponds to an example of the display section.

The light source section 111 includes a lamp such as a halogen lamp, axenon lamp, or an ultra-high pressure mercury lamp or a solid-statelight source such as an LED (Light Emitting Diode) or a laser lightsource. The light source section 111 may include a reflector that guideslight emitted by a light source to the light modulating device 112 andan auxiliary reflector. Further, the light source section 111 mayinclude a lens group and a polarizing plate for improving an opticalcharacteristic of projected light or a dimming element or the like forreducing, on a path leading to the light modulating device 112, a lightamount of the light emitted by the light source.

The light-source driving section 121 lights and extinguishes the lightsource of the light source section 111 according to an instruction of afirst control section 150.

The light modulating device 112 includes a light modulating element andmodulates the light emitted by the light source section 111 to generatethe image light PL. The light modulating device 112 includes, as thelight modulating element, for example, three liquid crystal panels 115corresponding to the three primary colors of R, G, and B. The liquidcrystal panels 115 may be transmission-type liquid crystal panels or maybe reflection-type liquid crystal panels. The light emitted by the lightsource section 111 is separated into, for example, color lights of thethree colors of R, G, and B and made incident on the liquid crystalpanels 115 corresponding to the color lights of R, G, and B andmodulated. The color lights are combined into the image light PL by acombination optical system such as a cross dichroic prism. The imagelight PL is emitted to the projection optical system 113. The lightmodulating element included in the light modulating device 112 is notlimited and may be, for example, a digital micromirror device.

The light modulating device 112 is driven by the light-modulating-devicedriving section 122. The light-modulating-device driving section 122 iscoupled to an image processing section 145.

Image data corresponding to the primary colors of R, C, and B are inputto the light-modulating-device driving section 122 from the imageprocessing section 145. The light-modulating-device driving section 122converts the input image data into a signal suitable for the operationof the liquid crystal panels 115. The light-modulating-device drivingsection 122 applies a voltage to the liquid crystal panels 115 based onthe converted signal and draws images on the liquid crystal panels 115.

The projection optical system 113 includes a lens, a mirror, and thelike for forming an image of the incident image light PL on the screenSC. The projection optical system 113 may include a zoom mechanism forenlarging or reducing an image projected onto the screen SC and a focusadjusting mechanism for adjusting a focus.

The projector 100 further includes an operation section 131, aremote-controller-light receiving section 133, an input interface 135, afirst storing section 137, an image interface 141, a frame memory 143,an image processing section 145, and a first control section 150. Thesesections are connected to one another via an internal bus 107 to becapable of performing data communication.

The operation section 131 includes not-shown operators such as buttonsand switches provided on a housing of the projector 100. The operationsection 131 receives operation on the operators, generates an operationsignal corresponding to the operation, and outputs the operation signalto the input interface 135. The input interface 135 outputs theoperation signal input from the operation section 131 to the firstcontrol section 150.

The remote-controller-light receiving section 133 receives an infraredsignal transmitted from a remote controller 5 and decodes the receivedinfrared signal to generate an operation signal. Theremote-controller-light receiving section 133 outputs the generatedoperation signal to the input interface 135. The input interface 135outputs the operation signal input from the remote-controller-lightreceiving section 133 to the first control section 150.

The operation section and the remote-controller-light receiving section133 correspond to an example of the receiving section.

The first storing section 137 is a nonvolatile storage device such as ahard disk drive or an SSD (Solid State Drive). The first storing section137 stores a program to be executed by a processor 153 explained belowand data to be processed by the processor 153.

The image interface 141 includes a connector and an interface circuitand is coupled to an image supply device different from the projector100. The image interface 141 corresponds to an example of the inputsection.

In this embodiment, the image interface 141 includes an HDMI connectorand an HDMI interface circuit. The image interface 141 executescommunication between the image interface 141 and the personal computer200 via the cable 10 according to the HDMI standard.

The image interface 141 may include a plurality of connectors and aplurality of interface circuits. For example, cables 11 and 12 may beconnectable to the image interface 141 besides the cable 10. As thecables 11 and 12, a USB (Universal Serial Bus) cable, a VGA cable, anEthernet (registered trademark) cable, and the like can be adopted. Forexample, the image interface 141 may be connectable to image supplydevices 21 and 22 via the cables 11 and 12. In this case, image data canbe input to the image interface 141 from each of the image supplydevices 21 and 22. The image interface 141 may include a communicationinterface circuit that executes data communication conforming to acommunication standard such as Ethernet.

The image supply device connectable to the image interface 141 only hasto be a device that outputs image data. Examples of the image supplydevice include a recording medium playing device such as a DVD player, amedia streaming device that acquires data via a communication line andoutputs image data based on the acquired data, and a communicationterminal device such as a smartphone. The number of image supply devicesconnectable to the image interface 141 is not limited.

The image interface 141 may have a function of a card reader that readsimage data from a portable recording medium such as an SD (registeredtrademark) card.

The image interface 141 may include a wireless communication interfacecircuit that executes wireless data communication. In this case, theimage interface 141 can acquire image data from the image supply devices21 and 22 or other devices by wireless communication.

Apparatuses and devices that supply image data to the image interface141 are collectively referred to as image source. When the imageinterface 141 is capable of using a plurality of image sources, theprojector 100 is capable of selecting any one of the plurality of imagesources. The first control section 150 may automatically perform theselection of the image source. For example, when priority of therespective image sources is decided in advance, the first controlsection 150 selects one image source according to the priority order.The first control section 150 may select an image source according tooperation received by the operation section 131 or operation performedusing the remote controller 5.

The image interface 141 may include a connector to which a cable fortransmitting an analog image signal is connectable and an interfacecircuit to which the analog image signal can be input. In this case, theimage interface 141 includes a conversion circuit that converts theanalog image signal into digital image signal.

The image interface 141 selects the image source according to control bythe first control section 150 and outputs image data input from theselected image source to the image processing section 145.

The first control section 150 includes a memory 151 and a processor 153.The first control section 150 corresponds to an example of the controlsection according to the present disclosure.

The memory 151 is a storage device that stores a program to be executedby the processor 153 and data. The memory 151 is configured by amagnetic storage device, a semiconductor storage element such as a flashROM (Read Only Memory), or a storage device of another type. The memory151 may include a RAM (Random Access Memory) configuring a work area ofthe processor 153. The memory 151 stores data to be processed by thefirst control section 150 and a control program to be executed by theprocessor 153.

The processor 153 may be configured by a single processor. A pluralityof processors may be configured to function as the processor 153. Theprocessor 153 executes the control program to control the sections ofthe projector 100. For example, the processor 153 selects, out of theimage sources coupled to the image interface 141, an image source thatoutputs an image to be displayed. The processor 153 controls the imageinterface 141 to output image data input from the image source to theimage processing section 145. The processor 153 outputs an executioninstruction for image processing and parameters used for the imageprocessing to the image processing section 145. The parameters include,for example, a geometrical correction parameter for correctinggeometrical distortion of an image projected onto the screen SC. Theprocessor 153 controls the light-source driving section 121 to controllighting and extinction of the light source section 111 and adjusts theluminance of the light source section 111.

The image processing section 145 and the frame memory 143 can beconfigured by, for example, an integrated circuit. The integratedcircuit includes an LSI, an ASIC (Application Specific IntegratedCircuit), and a PLD (Programmable Logic Device). For example, an FPGA(Field-Programmable Gate Array) is included in the PLD. An analogcircuit may be included in a part of the configuration of the integratedcircuit. The image processing section 145 and the frame memory 143 maybe a combination of a processor and an integrated circuit. Thecombination of the processor and the integrated circuit is calledmicrocontroller (MCU) SoC (System-on-a-chip), system LSI, chip set, andthe like.

The image processing section 145 develops the image data input from theimage interface 141 in the frame memory 143. The frame memory 143includes a plurality of banks. The banks have a storage capacity enoughfor writing image data for one frame. The frame memory 143 is configuredby, for example, an SDRAM (Synchronous Dynamic Random Access Memory).

The image processing section 145 performs, on the image data developedin the frame memory 143, image processing such as resolution conversionprocessing, resize processing, correction of distortion aberration,shape correction processing, digital zoom processing, or adjustment ofthe tint and the luminance of an image.

1-3. Configuration of the Control Section

FIG. 3 is a functional block diagram showing the configuration of acontrol system of the projector 100 and shows an example of theconfiguration of the first control section 150.

As shown in FIG. 3 , the first control section 150 of the projector 100includes a projection control section 156, a condition determiningsection 157, and an image-processing control section 158. The processor153 executes the control program stored in the memory 151, whereby thesefunctional sections are realized by cooperation of software andhardware. The first control section 150 includes setting data 159. Thesetting data 159 is stored in, for example, the memory 151.

The projection control section 156 controls the image interface 141 toselect an image source. The projection control section 156 controls thedriving section 120 and the image processing section 145 to display animage with the projecting section 110 based on image data input from theselected image source.

The condition determining section 157 determines whether an operationstate of the projector 100 and/or a state of the control by the firstcontrol section 150 satisfies preset conditions. The conditions to bedetermined by the condition determining section 157 are in the settingdata 159. In this embodiment, the condition determining section 157determines a first condition and a second condition. The first conditionis a condition for the projector 100 to display a second image generatedby modifying the image based on the image data input from the imagesource. The second condition is a condition for the projector 100 topermit display of a first image based on the image data input from theimage source.

The image-processing control section 158 controls the image processingsection 145 to generate the first image based on the image data andgenerate the second image by applying image processing to the firstimage. The image-processing control section 158 outputs, to the imageprocessing section 145, control data for designating a type of the imageprocessing applied to the first image and parameters of the imageprocessing.

The first image is an image displayed by normal processing based on theimage data input from the image source. In contrast, the second image isan image generated from, the first image, the image being different fromthe first image. Specifically, the second image is an image generated byapplying image processing for reducing visibility to the first image.The first image and the second image are explained below.

The setting data 159 includes data for deciding contents of the firstcondition and the second condition determined by the conditiondetermining section 157. The setting data 159 includes data fordesignating a type or image processing executed by the image processingsection 145 when it is determined that the first condition is satisfiedand parameters of the image processing.

1-4. Configuration of the Personal Computer

FIG. 4 is a block diagram, showing the configuration of the personalcomputer 200.

The personal computer 200 is a general-purpose computer of a desktoptype, a laptop type, or a tablet type.

The personal computer 200 includes a second control section 210 and asecond storing section 220.

The second control section 210 executes a program to thereby, executedata processing and controls sections of the personal computer 200.

The second control section 210 includes a processor 211 and a memory212. The memory 212 is a storage device that stores a basic controlprogram to be executed by the processor 211 and data. The memory 212 isconfigured by a magnetic storage device, a semiconductor storage elementsuch as a flash ROM, or a storage device of another type. The memory 212may include a RAM configuring a work area of the processor 211.

The second storing section 220 is a nonvolatile storage device such as ahard disk drive or an SSD. The second storing section 220 stores aprogram to be executed by the processor 211 and data to be processed bythe processor 211. The second storing section 220 stores a controlprogram 221 to be executed by the processor 211 and content data 222.The content data 222 is data of contents including videos, still images,sound, and texts. For example, the personal computer 200 reproduces thecontent data 222 to thereby display a video and a still image on a PCdisplay section 232. A data format of the content data 222 is notlimited. The content data 222 may be data processed by a specificapplication program executed by the processor 211.

The personal computer 200 includes an input section 231, a PC displaysection 232, a PC communication section 233, and an output interface234. These sections are coupled to the second control section 210 by abus 205.

The input section 231 includes a not-shown input device such as akeyboard, a mouse, or a trackpad and receives operation on the inputdevice. The input section 231 detects the operation on the input device,generates operation data indicating the detected operation, and outputsthe operation data to the second control section 210.

The PC display section 232 includes a display screen such as a liquidcrystal display panel and displays various screens according to controlby the second control section 210.

The PC communication section 233 includes a connector and acommunication interface circuit to which a communication cableconforming to the Ethernet standard is connectable. The PC communicationsection 233 executes data communication between the PC communicationsection 233 and external devices. The PC communication section 233 mayinclude a wireless communication interface conforming to a Wi-Fi(registered trademark) standard.

The output interface 234 transmits image data to devices on the outsideof the personal computer 200 according to the control by the secondcontrol section 210. The output interface 234 includes a connector andan interface circuit to which an image transmission cable such as thecable 10 is connectable. The output interlace 234 may include a wirelesscommunication interface that wirelessly transmits the image data. Inthis embodiment, the cable 10 is coupled to the output interface 234.The output interface 234 transmits the image data to the projector 100.

The second control section 210 executes data processing based on theoperation data input from the input section 231 and/or data received bythe PC communication section 233 and causes the PC display section 232to display a processing result or the like. For example, the secondcontrol section 210 performs processing for reproducing the content data222 stored by the second storing section 220 and causes the PC displaysection 232 to display an image of the content data 222.

The second control section 210 can execute processing for causing bothof the PC display section 232 and a display device coupled via theoutput interface 234 to display an image. In this embodiment, the outputinterface 234 is coupled to the projector 100. In this case, the secondcontrol section 210 executes a display mode in which the PC displaysection 232 and the projector 100 are used.

For example, the second control section 210 is capable of switching amirroring mode and an extension mode. In the mirroring mode, the secondcontrol section 210 causes the projector 100 to display the same contentas content displayed on the PC display section 232. In the mirroringmode, the PC display section 232 and the projector 100 perform the samedisplay. A state in which the PC display section 232 and the projector100 perform the same display includes a state in which processing forcorrecting display resolutions and color tones of the PC display section232 and the projector 100 is applied. The mirroring mode corresponds tothe first operation state and the extension mode corresponds to thesecond operation state.

In the extension mode, the second control section 210 causes the PCdisplay section 232 and the projector 100 to display different contents.In the extension mode, the second control section 210 can use theprojector 100 as a second display section that extends a display regionof the PC display section 232. As an example of use of the extensionmode, the second control section 210 causes the PC display section 232to display a screen concerning basic functions of the projector 100 andcauses the projector 100 to display a screen of a specific applicationprogram executed by the second control section 210. In this case, thereis an advantage that the user who operates the personal computer 200 canuse a large display region as if the display region of the PC displaysection 232 is extended by the projector 100.

Data output from the output interface 234 to the projector 100 includesdata capable of distinguishing whether the personal computer 200 is inthe mirroring mode or the extension mode. The data may be, for example,a flag indicating whether the personal computer 200 is in the extensionmode. Consequently, the projector 100 can detect, based on the imagedata input from the personal computer 200, whether the personal computer200 is in the extension mode.

1-5. Image Processing

FIG. 5 shows an example of the first image displayed by the projector100. FIGS. 6, 7, and 8 show examples of the second image displayed bythe projector 100. The first image and the second image displayed by theprojector 100 are explained with reference to these figures.

The first image is an image displayed in normal processing based onimage data input from an image source. In contrast, the second image isan image generated from the first image, the image being different fromthe first image. Specifically, the second image is an image generated byapplying image processing for reducing visibility to the first image.

Examples of the image processing for generating the second image fromthe first image include mosaic processing, shading processing, andwarping processing.

The mosaic processing is image processing for setting a rectangle havingany size in the first image and painting out pixels present in a rangeof the rectangle in the same color.

A first image 310 includes display objects 311, 312, and 313. Thedisplay objects 311 and 312 are display objects having rectangularframes and are, for example, windows displayed by an operating system ofthe personal computer 200. The display object 313 is a text arranged inthe frame of the display object 312.

The first image 310 is an image having predetermined resolution and isformed by a plurality of pixels arranged side by side in thelongitudinal direction and the lateral direction. The resolution of thefirst image 310 is optional. For example, the image processing section145 adjusts the resolution of an image according to the displayresolution of the liquid crystal panels 115 and generates the firstimage 310. In the following explanation, a color of the pixels formingthe image 310 can be rephrased as color data of the pixels or can berephrased as a gradation value of the pixels.

A second image 320 is shown in FIG. 6 as an example of an imagegenerated by the mosaic processing.

The second image 320 is an image generated by applying the mosaicprocessing to the entire first image 310. The mosaic processing isprocessing for arranging a rectangle including a plurality of pixels ina part of or the entire first image 310 and changing colors of thepixels: included in the rectangle to the same color. When the mosaicprocessing is applied to the entire first image 310, the imageprocessing section 145 divides the first image 310 into a plurality ofrectangles and changes colors of pixels included in the rectangles tothe same color. As the number of pixels included in the rectangles islarger, the intensity of the mosaic processing increases and thevisibility of the second mage 320 decreases. The first control section150 may determine the color of the rectangles based on an average ofcolor data of the pixels included in the rectangles. The color of therectangles may be a color of a specific pixel included in the rectanglesor may be set by the setting data 159 in advance. The number of pixelsincluded in the rectangles may also be set by the setting data 159 inadvance.

Since the mosaic processing is applied to the second image 320, thecontours of display objects 321, 322, and 323 are blurred. For example,characters included in the display object 323 subjected to the mosaicprocessing are images hard to be read.

A second image 330 is shown in FIG. 7 as an example of an imagegenerated by the shading processing.

The second image 330 is an image generated by applying the shadingprocessing to the entire first image 310. The shading processing isprocessing for converting the color of the specific pixel forming thefirst image 310 based on the color of the specific pixel and a color ofpixels located around the specific pixel. The conversion processing is,for example, processing for reducing a difference between the colors.Specifically, the color of the specific pixel is replaced with anaverage of pixel values of the pixels around the specific pixel by theconversion processing. In this case, when the average is calculated, anarithmetic operation for changing weight according to the distancebetween the specific pixel and the pixels around the specific pixel maybe performed. Alternatively, the color of the specific pixel may beconverted into a median of the pixel values around the specific pixel bythe conversion processing. In the shading processing, as the number ofperipheral pixels used for the conversion processing is larger, theintensity of the shading processing increases and the visibility of thesecond image 330 further deteriorated.

The shading processing is called soothing processing or blur processingas well. The shading processing can be executed by, for example,filtering performed using a filter for smoothing the color of thepixels. Parameters such as the position of the specific pixel, thenumber of peripheral pixels, a degree of smoothing, and the number oftimes of repetition of the shading processing in the shading processingmay be determined based on the color of the specific pixel and anaverage of the colors of the plurality of pixels included in the firstimage 310. The parameters may be set in advance by the setting data 159.The projector 100 may repeatedly apply the shading processing to theimage subjected to the shading processing.

The second image 330 is an image generated by performing the shadingprocessing by setting all pixels forming the first image 310 as specificpixels or arranging the specific pixel for each predetermined number ofpixels. Since the shading processing is applied to the second image 330,the contours of the display objects 331, 332, and 333 are blurred. Forexample, characters included in the display object 333 subjected to theshading processing are an image hard to be read.

A second image 340 is shown in FIG. 8 as an example of an imagegenerated by the warping processing.

The second image 340 is an image generated by applying the warpingprocessing to the entire first image 310. The warping processing isprocessing for giving coordinates in an X-Y orthogonal coordinate systemto the pixels forming the first image 310 and converting thecoordinates. For example, a pixel in a coordinate (x, y) is mapped toanother coordinate (x′, y′) By performing this processing on all thepixels forming the first image 310 or a part of the pixels selected atan interval of predetermined pixels, the warping processing can beapplied to the entire first image 310. In the warping processing,processing for moving coordinates of the pixels in an X-axis direction,processing for moving the coordinates of the pixels in a Y-axisdirection, processing for moving the coordinates of the pixels in bothof the X-axis direction and the Y-axis direction, and the like can beperformed. The intensity of the warping processing increases and thevisibility of the second image 340 is deteriorated as the number ofpixels, coordinates of which are converted, is larger and a movementamount of coordinates of the pixels is larger. The warping processingmay be repeatedly applied to an image subjected to the warpingprocessing. The warping processing includes processing called warpdeformation processing and geometric conversion processing.

A form of the second image 340 generated by the warping processing is animage distorted to form a wave or an image distorted to draw a swirl.The second image 340 shown in FIG. 8 is an image generated by applyingthe warping processing to the entire first image 310. The second image340 is distorted to draw a swirl. The rectangles of the display objects341 and 342 are deformed. The display object 343 is distorted to adegree unreadable as characters.

In this way, the projector 100 is capable of generating the secondimages 320, 330, and 340 generated by reducing readability of contentsuch as characters from readability of the first image 310 obtained fromthe image data input to the image processing section 145. The projector100 is capable of executing at least any one of the mosaic processing,the shading processing, and the warping processing explained above andmay be capable of executing any one or more kinds of the processingselectively or in combination.

The second image is an image generated based on the first image, theimage being obtained by reducing the visibility of the first image. Itis more preferable that the second image is an image from which contentof the first image can be estimated. In other words, it is preferablethat the second image has not completely lost similarity to the firstimage. For example, the second image 320 is similar to the first image310 in that the display objects 321 and 322 are the rectangles and in apositional relation between the display objects 321 and 322. The displayobject 323 cannot be read as characters. However, the user can recognizethat the display object 323 is a character string. Therefore, viewingthe second image 320, the user can estimate that the first image is thefirst image 310 and determine whether the first image 310 is an imagesuitable for display or an image not desired to be displayed.

1-6. Operation of the projector

FIG. 9 is a flowchart showing the operation of the projector 100.Processing shown in FIG. 9 can be executed by the first control section150.

The first control section 150 determines whether an input of new imagedata to the image interface 141 has been detected (step S11). In stepS11, when the image supply devices 21 and 22 or the personal computer200 starts an output of image data to the image interface 141, anaffirmative determination is made. When an input of new image data hasbeen detected (YES in step S11), the first control section 150 shifts tostep S13 explained below.

When an input of new image data is not detected (NO in step S11), thefirst control section 150 determines whether switching of an imagesource has been instructed (step S12). In step S12, when the operationsection 131 or the remote-controller-light receiving section 133receives operation for instructing switching of the image source, thefirst control section 150 makes an affirmative determination. Whenswitching of the image source is instructed (YES in step S12), the firstcontrol section 150 shifts to step S13. When switching of the imagesource is not instructed (NO in step S12), the first control section 150shifts to step S22.

In step S13, the first control section 150 determines that the firstcondition is satisfied and switches the image source. That is, in thisembodiment, the first condition is that new image data is input to theimage interface 141 or switching of the image source is instructed bythe user. In step S13, the first control section 150 causes the imageinterface 141 to select the new input image data detected in step S11 orthe image source instructed to be switched in step S12.

When the image source selected by the image interface 141 is thepersonal computer 200, the first control section 150 detects anoperation state of the personal computer 200 (step S14). In step S14,the first control section 150 refers to control data input from thepersonal computer 200 together with the image data and detects whetherthe personal computer 200 is in the extension mode.

The first control section 150 determines whether the personal computer200 is in the extension mode (step S15). When determining that thepersonal computer 200 is in the extension mode (YES in step S15), thefirst control section 150 shifts to step S22 explained below.

When determining that the personal computer 200 is not in the extensionmode (NO in step S15), the first control section 150 refers to thesetting data 159 (step S16). When the image source selected by the imageinterface 141 is not the personal computer 200, the first controlsection 150 also shifts to step S16. In this case, the first controlsection 150 may omit steps S14 and S15.

In step S16, the first control section 150 acquires setting contentconcerning generation of the second image from the setting data 159.

The first control section 150 controls the image processing section 145according to the setting data 159 to start processing for generating thesecond image from the first image (step S17). The first control section150 causes the projecting section 110 to start display of the secondimage generated by the image processing section 145 (step S10).

The first control section 150 calculates an elapsed time after thedisplay of the second image is started in step S18, that is, a displaytime of the second image (step S19). The first control section 150determines, based on the display time calculated in step S19, whether afirst period has elapsed after the display of the second image isstarted (step S20). When the first period has not elapsed (NO in stepS20), the first control section 150 repeatedly performs the processingin step S19.

When the first period has elapsed (YES in step S20), the first controlsection 150 determines that the second condition is satisfied (stepS21). That is, in this embodiment, the second condition is that thefirst period elapses after the display of the second image is started.The first control section 150 shifts to step S22.

In step S22, the first control section 150 controls the image processingsection 145 to generate the first image based on the image data input tothe image interface 141 and causes the projecting section 110 to startdisplay of the first image.

The first control section 150 determines whether to end the display(step S23). For example, when operation for instructing a display end isreceived by the operation section 131 or the remote-controller-lightreceiving section 133, the first control section 150 makes anaffirmative determination. When determining to end the display (YES instep S23), the first control section 150 stops the display by theprojecting section 110 and ends this processing. When determining not toend the display (NO in step S23), the first control section 150 returnsto step S11.

1-7. Action Effect in the First Embodiment

As explained above, the projector 100 according to this embodimentincludes the projecting section 110 that displays an image and the imageinterface 141 to which an image signal corresponding to the first imageis input from the personal computer 200. The projector 100 includes theimage processing section 145 that processes the first image based on theimage signal and generates the second image obtained by reducing thevisibility of the first image. The projector 100 includes the firstcontrol section 150 that, when the first condition is satisfied, causesthe projecting section 110 to display the second image and, when thesecond condition is satisfied, causes the projecting section 110 todisplay the first image.

The display system 1 includes the projector 100 including the projectingsection 110 that displays an image and the personal computer 200 thatinputs an image signal corresponding to the first image to the projector100. The projector 100 includes the image processing section 145 thatprocesses the first image based on the image signal and generates thesecond image obtained by reducing the visibility of the first image. Theprojector 100 includes the first control section 150 that, when thefirst condition is satisfied, causes the projecting section 110 todisplay the second image and, when the second condition is satisfied,causes the projecting section 110 to display the first image.

With a display control method in the projector 100, the first image isprocessed based on an image signal of the first image input from thepersonal computer 200 to generate the second image obtained by reducingthe visibility of the first image. When the first condition issatisfied, the projecting section 110 is caused to display the secondimage. When the second condition is satisfied, the projecting section110 is caused to display the first image.

With the projector 100, the display system 1 including the projector100, and the display control method in the projector 100, the followingaction effects are obtained.

When the first condition is satisfied, the second image obtained byreducing the visibility of the first image is displayed by the projector100. For example, if the first condition and the second condition areset to display the second image earlier than the first image, the secondimage is displayed earlier than the first image. In this case, when thefirst image is an image not desired to be made public, display of thefirst image can be prevented. Since the second image is generated from,the first image, the user can estimate content of the first image fromthe second image displayed by the projector 100. Accordingly, the usercan determine, based on the second image, whether the first image is animage that may be made public.

When the second condition is satisfied in a state in which the secondimage is displayed, the projector 100 may switch the image displayed bythe projecting section 110 from the second image to the first image. Inthis case, in a state in which the second image is displayed earlier,the user can determine whether the first image may be displayed.

The first condition is that an input of an image signal to the imageinterface 141 is started in this case, when an image signal is input tothe image interface 141 included in the projector 100, the first imageis not displayed and the second image is displayed. Accordingly, forexample, even if an image input to the image interface 141 anew is animage not desired to be displayed, it is possible to prevent such animage from being clearly displayed. Even if a display start of an imageis not instructed according to the input of the image signal to theimage interface 141, it is possible to switch the image displayed by theprojecting section 110. There is an advantage that convenience is high.

The first condition is that processing for causing the projectingsection 110 to display the first image is started. In this case, whenprocessing for displaying an image based on an image signal input to theimage interface 141 is started, first, the second image is displayed bythe projecting section 110. The processing for displaying the firstimage is, for example, processing in which the first control section 150selects or switches an image source. In this case, for example, even ifan image input anew is an image not desired to be displayed, it ispossible to prevent such an image from being clearly displayed.Accordingly, even if an image input from the image source cannot bechecked before the image source is switched, it is possible to preventthe image not desired to be displayed from being displayed on the screenSC.

The second condition is that the first period elapses after the firstcontrol section 150 causes the projecting section 110 to display thesecond image. In this case, when the first period elapses after thesecond image is displayed, the first image is displayed. The user onlyhas to determine, within the first period, whether the first image maybe displayed. When the first image is an image that may be displayed, ifthe user waits until the first period elapses, the first image isdisplayed. Therefore, operation by the user is simple.

When the first image is an image not desired to be displayed, it ispossible to prevent display of the first image if the display of theprojector 100 is stopped before the first period elapses.

In this embodiment, the second condition may be that the input of animage signal to the image interface 141 and the processing for causingthe projecting section 110 to display the second image are started andthe first period elapses after later one of the input and the processingis started. Specifically, when the first period has elapsed startingfrom later timing of timing when the input is detected in step S11 andtiming when the display of the second image is started in step S18, thefirst control section 150 determines that the second condition issatisfied. In this case, the second image is surely displayed for thefirst period until the second condition is satisfied. Accordingly, theuser can secure a time for determining whether the first image is animage that may be displayed.

For example, the image processing section 145 applies the mosaicprocessing to the first image to thereby generate the second image. Inthis case, it is possible to easily generate, as the second image, animage obtained by reducing the visibility of the first image with themosaic processing, the user being capable of estimating content, of thefirst image from the image.

For example, the image processing section 145 applies the shadingprocessing to the first image to thereby generate the second image. Inthis case, it is possible to easily generate, as the second image, animage obtained by reducing the visibility of the first image with theshading processing, the user being capable of estimating content of thefirst image from the image.

For example, the image processing section 145 applies the warpingprocessing to the first image to thereby generate the second image. Inthis case, it is possible to easily generate, as the second image, animage obtained by reducing the visibility of the first image bydeforming the first image, the user being capable of estimating contentof the first image from the image.

The first control section 150 detects an operation state of the personalcomputer 200 and, when the personal computer 200 is in the firstoperation state, causes the projecting section 110 to display the secondimage when the first condition is satisfied. When the personal computer200 is in the second operation state, the first control section 150causes the projecting section 110 to display the first image withoutcausing the projecting section 110 to display, the second image. Asexplained above, the first operation state of the personal computer 200is, for example, the mirroring mode and the second operation state ofthe personal computer 200 is, for example, the extension mode. When thepersonal computer 200 is in the extension mode, an image input from thepersonal computer 200 to the projector 100 is an image different from animage displayed on the PC display section 232. Accordingly, it is highlylikely that the first image based on the image data input from thepersonal computer 200 is an image that may be displayed by the projector100. In such a case, the first control section 150 does not display thesecond image. Therefore, there is an advantage that it is possible toquickly display an image output by the personal computer 200 on thescreen SC.

2. Second Embodiment

FIG. 10 is a flowchart showing the operation of the projector 100 in asecond embodiment to which the present disclosure is applied. In FIG. 10, processing common to FIG. 9 is denoted by the same step numbers andexplanation about the processing is omitted.

The second embodiment is another operation example of the projector 100explained in the first embodiment. Accordingly, since the configurationsor the sections of the display system 1 in the second embodiment arecommon to the first embodiment, illustration and explanation about theconfigurations are omitted.

In the second embodiment, after determining in step S20 that the firstperiod has elapsed (YES in step S20), the first control section 150shifts to an instruction waiting state (step S31). In the instructionwaiting state, the first control section 150 waits for, with theoperation section 131 and/or the remote-controller-light receivingsection 133, operation for instructing display of the first image. Thefirst control section 150 determines presence or absence of theoperation for instructing display of the first image (step S32) and,while the relevant operation is absent (NO in step S32), continues theinstruction waiting state in step S31. When receiving the operation forinstructing display of the first image (YES in step S32), the firstcontrol section 150 determines in step S21 that the second condition issatisfied.

That is, in the second embodiment, when the first period elapses afterthe display of the second image is started and when the operation forinstructing display of the first image is performed, the first controlsection 150 determines that the second condition is satisfied.

As explained above the projector 100 in the second embodiment includesthe operation section 131 and the remote-controller-light receivingsection 133 as the receiving section that receives operation. The secondcondition is that, after the first period elapses, the operation forinstructing display of the first image is received by the receivingsection. Consequently, while the operation for instructing display, ofthe first image is not performed, the display of the second image iscontinued even if the first period elapses. Accordingly, when the firstimage is an image not desired to be displayed, it is possible to preventthe first image from being displayed on the screen SC. It is possible tocause the screen SC to display the first image after the user confirmsthat the first image is not an image not desired to be displayed.

3. Third Embodiment

FIG. 11 is a flowchart showing the operation of the projector 100 in athird embodiment to which the present disclosure is applied. In FIG. 11, processing common to FIG. 9 is denoted by the same step numbers andexplanation of the processing is omitted.

The third embodiment is another operation example of the projector 100explained in the first embodiment. Accordingly, the configurations ofthe sections of the display system 1 in the third embodiment are commonto the first embodiment. Therefore, illustration and explanation aboutthe configurations are omitted.

In the third embodiment, after causing the projecting section 110 todisplay the second image in step S18, the first control section 150determines whether operation for instructing display of the second imagehas been performed (step S41). In step S41, the first control section150 waits for, with the operation section 131 and/or theremote-controller-light receiving section 133, operation for instructingdisplay of the second image. Specifically, this operation is aninstruction to continue the display of the second image.

When the operation for instructing display of the second image is notperformed (NO in step S41), the first control section 150 calculates adisplay time of the second image (step S19). The first control section150 determines whether the first period has elapsed after the display ofthe second image is started (step S20). When the first period has notelapsed (NO n step S20), the first control section 150 returns to stepS41.

When determining that the operation for instructing display of thesecond image has been performed (YES in step S41), the first controlsection 150 shifts to an instruction waiting state (step S42). Theinstruction waiting state in step S42 is a state in which the firstcontrol section 150 waits for, with the operation section 131 and/or theremote-controller-light receiving section 133, the operation forinstructing display of the first image. In the instruction waiting statein step S42, the projecting section 110 continues the display of thesecond image.

The first control section 150 determines presence or absence of theoperation for instructing display of the first image (step S43) and,while the relevant operation is absent (NO in step S43), continues theinstruction waiting state in step S42. When receiving the operation forinstructing display of the first image (YES in step S43), the firstcontrol section 150 determines in step S21 that the second condition issatisfied.

That is, in the third embodiment, when the instruction to continuedisplaying the second image is performed after the display of the secondimage is started, the first control section 150 shifts to theinstruction waiting state. In this case, the first control section 150continues the display of the second image until the operation forinstructing display of the first image is performed.

In the third embodiment, when the first period has elapsed while theinstruction to continuously display the second image is not performedafter the display of the second image is started, the first controlsection 150 determines that the second condition is satisfied.

In this way, in the projector 100 in the third embodiment when the firstperiod has elapsed in the state in which the operation for instruct ngcontinuation of the display of the second image is not received, thefirst control section 150 determines that the second condition issatisfied. When the operation for instructing continuation of thedisplay or the second image is received before the first period elapsesafter the first control section 150 causes the projecting section 110 todisplay the second image, the first control section 150 causes theprojecting section 110 to continue the display of the second image.Accordingly, according to operation by the user, even if the firstperiod has elapsed, it is possible to continue the display of the secondimage. When the first image is an image not desired to be displayed, itis possible to prevent the first image from being displayed on thescreen SC. It is possible to cause the screen SC to display the firstimage after the user confirms that the first image is not an image notdesired to be displayed.

Further, when the operation for instructing continuation of display ofthe second image is received, according to the operation for instructingdisplay of the first image, it is possible to change the image displayedby the projecting section 110 to the first image. Accordingly, it ispossible to quickly display the first image according to operation bythe user. Therefore, it is possible to execute the continuation of thedisplay of the second image and the switching to the display of thefirst image at timing requested by the user without being limited to theelapse of the first period.

4. Other Embodiments

The embodiments explained above are preferred modes of implementation.However, the preferred modes of implementation are not limited to theembodiments. Various modified implementations are possible within arange not departing from the gist.

For example, in the operation example explained in the embodiments, theprojector 100 displays the first image and the second image based on theimage data output to the projector 100 by the personal computer 200. Thepresent disclosure is not limited to this. The projector 100 may displaythe first image and the second image based on image data and imagesignals output by the image supply devices 21 and 22.

The projector 100 in the embodiments includes the operation section 131and the remote-controller-light receiving section 133 as the receivingsection that receives operation. However, the projector 100 may receiveoperation with other configurations. For example, the projector 100 maybe capable of wirelessly receiving control data including a command froma device such as a smartphone by wireless communication such as Wi-Fi.In this case, the projector 100 may receive, as operation, the commandincluded in the control data.

For example, the display device according to the present disclosure isnot limited to the projector that projects an image onto the screen SCand may be a liquid crystal display that displays an image on a liquidcrystal display panel. The display device according to the presentdisclosure may be a display device that displays an image on a plasmadisplay panel or an organic EL (Electro Luminescence) panel. In thiscase, the liquid crystal display panel, the plasma display panel, or theorganic EL panel corresponds to an example of the display section.

The functional sections shown in FIGS. 2, 3, and 4 indicate functionalcomponents. Specific implementation forms of the functional sections arenot particularly limited. For example, hardware individuallycorresponding to the functional sections does not always need to beimplemented. It is also naturally possible to adopt a configuration inwhich one processor executes a program to realize functions of aplurality of functional sections. A part of the functions realized bysoftware in the embodiment may be realized by hardware or a part of thefunctions realized by hardware may be realized by software. Besides, thespecific detailed configurations of the other sections of the projector100 can also be optionally changed in a range not departing from thegist.

The processing units of the flowcharts of FIGS. 9, 10, and 11 aredivided according to the main processing contents in order to make iteasy to understand the processing of the first control section 150. Theprocessing units can also be divided into larger number of processingunits according to processing contents without being limited by the waysand the names of the divisions of the processing units shown in theflowcharts. The processing units can also be divided such that oneprocessing unit includes larger number of kinds of processing. Theprocessing order of the flowcharts is not limited to the example shownin the figures.

A control method for the projector 100 functioning as the display devicecan be realized by causing the processor 153 included in the projector100 to execute a control program corresponding to the control method forthe projector 100. The control program can also be recorded in arecording medium in which the control program is computer-readablyrecorded. The control method for the projector 100 can also be realizedby storing the control program corresponding to the control method forthe projector 100 in a server device or the like and downloading thecontrol program from the server device to the projector 100.

What is claimed is:
 1. A display device comprising: a display sectionconfigured to display an image; an interface circuit to which an imagesignal corresponding to a first image is input from an image supplydevice; an integrated circuit configured to generate a second imageobtained by reducing visibility of the first image based on the imagesignal; and a processor programmed to, when a first condition issatisfied, cause the display section to display the second image and,when a second condition is satisfied, cause the display section todisplay the first image wherein, the integrated circuit applies mosaicprocessing, shading processing or warping processing to the first imageto thereby generate the second image, wherein the first condition isthat new image data is input to the interface circuit or switching ofthe image supply device is instructed by a user, and wherein theprocessor is further programmed to, after the second image is displayed,if no input from the user is detected for a first period, automaticallydisplay the first image.
 2. The display device according to claim 1,wherein the second condition is that both of the input of the imagesignal to the interface circuit and processing for causing the displaysection to display the second image are started and a first periodelapses after later one of the input and the processing is started. 3.The display device according to claim 1, further comprising a receiverconfigured to receive operation, wherein the second condition is that,after the first period elapses, operation for instructing the display ofthe first image is received by the receiver.
 4. The display deviceaccording to claim 1, further comprising a receiver configured toreceive operation, wherein when the first period elapses in a state inwhich operation is not received by the receiver after the processorcauses the display section to display the second image, the processordetermines that the second condition is satisfied, and when operation isreceived by the receiving section before the first period elapses afterthe processor causes the display section to display the second image,the processor continues the display of the second image.
 5. A displaydevice comprising: a display section configured to display an image; aninterface circuit to which an image signal corresponding to a firstimage is input from an image supply device; an integrated circuitconfigured to generate a second image obtained by reducing visibility ofthe first image based on the image signal; and a processor programmedto, when a first condition is satisfied, cause the display section todisplay the second image and, when a second condition is satisfied,cause the display section to display the first image, wherein theprocessor detects an operation state of the image supply device, whenthe image supply device is in a first operation state, the processorcauses the display section to display the second image when the firstcondition is satisfied, and when the image supply device is in a secondoperation state, the processor causes the display section to display thefirst image without causing the display section to display the secondimage, wherein the first condition is that new image data is input tothe interface circuit or switching of the image supply device isinstructed by a user, and the processor is further programmed to, afterthe second image is displayed, if no input from the user is detected fora first period, automatically display the first image.
 6. The displaydevice according to claim 5, wherein the second condition is that bothof the input of the image signal to the interface circuit and processingfor causing the display section to display the second image are startedand a first period elapses after later one of the input and theprocessing is started.
 7. The display device according to claim 5,further comprising a receiver configured to receive operation, whereinthe second condition is that, after the first period elapses, operationfor instructing the display of the first image is received by thereceiver.
 8. The display device according to claim 5, further comprisinga receiver configured to receive operation, wherein when the firstperiod elapses in a state in which operation is not received by thereceiver after the processor causes the display section to display thesecond image, the processor determines that the second condition issatisfied, and when operation is received by the receiving sectionbefore the first period elapses after the processor causes the displaysection to display the second image, the processor continues the displayof the second image.
 9. The display device according to claim 5, whereinthe integrated circuit applies mosaic processing to the first image tothereby generate the second image.
 10. The display device according toclaim 5, wherein the integrated circuit applies shading processing tothe first image to thereby generate the second image.
 11. The displaydevice according to claim 5, wherein the integrated circuit applieswarping processing to the first image to thereby generate the secondimage.
 12. A display device comprising: a display section configured todisplay an image; an interface circuit to which an image signalcorresponding to a first image is input from an image supply device; anintegrated circuit configured to generate a second image obtained byreducing visibility of the first image based on the image signal; and aprocessor programmed to, when a first condition is satisfied, cause thedisplay section to display the second image and, when a second conditionis satisfied, cause the display section to display the first image,wherein, the first condition is that new image data is input to theinterface circuit or switching of the image supply device is instructedby a user, and the processor is further programmed to, after the secondimage is displayed, if no input from the user is detected for a firstperiod, automatically display the first image.